Mockito enables mocks creation, verification and stubbing.
A mock is an object that can simulate the behaviour of another object. This allows unit tests to be written easier.
Mocks automatically record all invocations they receive.
Mocks can be inspected after use.
Useful links
https://bitbucket.org/loomis/mockito-flex/wiki/Home
https://code.google.com/p/mockito/